Ok.. it was below zero last night with the wind chill. Every night I close the 5 girls in the coop which has a heated waterer but no other form of heat. They have a solar LED light but that throws no heat. Today it is about 12 degrees and when I went to let them out I noticed one or maybe two of the girls have frost bite on their heads. They are 6 months old and this is their first winter. What do I do now? What should I do different?